Added experimental data and plot file

kokkos-testing/experimental_data/timings.plot

+set term postscript enhanced color
+set output 'timing.eps'
+
+set title '2D damped wave equation, 1024x1024 grid'
+
+set style data histogram
+set style fill solid border -1
+set logscale y
+set grid ytics mytics
+plot 'timings2.txt' using 2:xtic(1) ti col, '' u 3 ti col, '' u 4 ti col, '' u 5 ti col, '' u 6 ti col, '' u 7 ti col

kokkos-testing/experimental_data/timings2.txt

+"order"     "Baseline"  "Serial"   "1 thread"   "2 threads"  "4 threads" "CUDA baseline"
+"2th order" 0.00707879  0.0141107  0.0138042   0.0072022  0.00539084
+"8th order" 0.033213    0.0419782  0.0409406   0.020956   0.0134292 0.0015